The scientific output on HIV/AIDS in Latin America is heterogeneous, reflecting broad social and economic forces, favouring/hampering science in general and research on HIV/AIDS in particular.

According to the ISI-Web of Science, (10) Brazil figures among the top 20 countries in scientific branches as diverse as plant science and neurosciences. In the field of HIV/AIDS, Brazil’s scientific output has been vigorous. (11,12) To some extent, other Latin American countries such as Argentina, Mexico and Peru have a consistent scientific output, but peer-reviewed publications from other Latin American countries on HIV/ AIDS are still scant.

Due to this heterogeneity, this review combines the thorough search of international (e.g. Pubmed and ISI-Web of Science) and regional databases, such as Scielo (The Scientific Electronic Library Online) and Lilacs (Latin American and Caribbean Health Sciences), with information from the gray literature (e.g. regional and national reports).

Even with the recourse to the abovementioned sources of information, data remained fragmentary and/or outdated for some countries. Additional data were sought from colleagues from UNAIDS.

Resultados: el status de la epidemia

Mexico

With more than 107 million population, Mexico, as of November 2006, had an estimated 182.000 people living with HIV/AIDS, with an HIV infection prevalence rate, in adults, estimated as 0.3% (95%CI: 0.2–0.7).(13)

Mexico’s epidemic remains concentrated in MSM, female sex workers (FSW) and their clients, and has been growing among injecting drug users (IDU). Unprotected sex between men is estimated to account for 57% of HIV infections reported as of December 2007.(14)

The epidemic is concentrated in the capital, Mexico City, and other large cities, as well as in the coastal area, due to the influx of tourists and workers of the tourism industry,(15) and, more recently, in the Mexico-United States (US) border.(16)

In 2000, only 4.6% of AIDS cases were from rural areas. However, in the present decade the epidemic has been increasing in villages and rural areas, where native Mexicans predominate.(15) The seasonal migration of Mexicans between the US and their rural hometowns in Mexico may contribute to the dissemination of HIV.17 In recent years, heterosexual transmission became more relevant and nowadays constitutes the main transmission route in the Mexican southern border.(18)

Mexico has been a transshipment area of cocaine en route to the US and in some of its regions poppy opium has been cultivated. Notwithstanding this, the injection of illicit drugs is relatively recent, and remains concentrated in the northern area adjacent to the US border.19 Drug using patterns have been changing, with increasing use of crack cocaine and meta-amphetamines, besides the injection of heroin.20

In Tijuana and Ciudad Juarez (Mexico-US border), drug consumption has been intense, with high levels of needle-sharing and low frequencies of HIV testing.16,21 In both cities prevalences of HIV among IDU remain relatively low (<5%), unlike syphilis, especially in Tijuana (13.5%), and HCV (hepatitis C virus) infections in both cities (~95%). (22) In Tijuana and Ciudad Juarez, studies among over 400 FSW in each city found that 21 and 12%, respectively, of FSW were also IDU, among whom HIV prevalence was found to be 16% (vs 4% in non-IDU FSW). Male sex workers are another highly vulnerable group, with prevalences over 20% in Mexico City/Guadalajara.(17)

América Central

Central America—consisting of Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua and Panama—is the subregion most affected by the HIV epidemic in Latin America. Guatemala and Honduras have generalized epidemics (i.e. prevalence rates among the general population 41%), while Costa Rica, El Salvador, Panama and Nicaragua have concentrated ones.1 Although declines have been observed in some countries, such as Honduras, the epidemic has not been curbed in certain populations and geographical areas, such as in the Garı´funa ethnic community (23) and in transit routes and ports.1

Efforts to curb the epidemic in the region have been hampered by poverty, lack of access to services and widespread stigma and discrimination.(1,24,25)

Information comes mainly from HIV Multicentric Studies conducted by UNAIDS/WHO and the National AIDS Programs in 2001–06.(24)

Indigenous populations, e.g. Cunas, Miskitos, Garifuna, Mayans and Xinca have been particularly vulnerable to the epidemic, due to overt marginalization. Five per cent of new infections in the region have occurred in Garifuna living in Belize, Guatemala, Nicaragua and Honduras, with an overall HIV prevalence of 4.5%. (23,25)

High prevalence for sexually transmitted infections (STI)24 and regular migrations between people living in Central America and in the US, add new layers of complexity to the local HIV dynamic. Around 139 000 Guatemalans of Mayan-descent live in the US and their numbers have been increasing.(25) The link between migration and vulnerability to HIV among Garifuna was recently assessed.(23)

All Central American countries have been experiencing the feminization of the epidemic since the early 1990s. In El Salvador the male : female ratio has oscillated around 1.5 : 1 in 2004–06,6 however, in areas with a lower Human Development Index, this ratio has been closer to 1 : 1 (e.g. the rural departments of Morazan and La Paz), or lower than 1 : 1, in Chalatenando.26 HIV prevalence among pregnant women is still low throughout Central America. In Honduras and El Salvador, in 2006, HIV prevalence was 0.6 and <0.5% among women accessing prenatal services, respectively.(1,26)

High infection rates have been found among FSW from Honduras, with a high seroincidence (3.2/100 person-years), whereas rates have been low in Nicaragua (0.2%) and Panama (0.2%).(1,24) Data on MSM are scarce due to stigmatization and denial. The multicenter survey of 2000–01 made evident a high HIV seroprevalence among MSM in El Salvador (15.3%) and Nicaragua (7.6%).24 Data from Honduras from 2006 also showed high prevalences in this population (6.0% in Tegucigalpa, 10.1% in San Pedro Sula and 5.0% in La Ceiba).27 Guatemala estimated an HIV prevalence between 11.5% and 18.3% among MSM, in 2007.(28)

With a total population of 43 593 000, the estimated prevalence of HIV among adults in Colombia was 0.6% in 2005.1 A total of 10 588 AIDS cases were reported between 1983 and 2005, of which 56% were reported as heterosexual and 44% as resulting from male-to-male sex.34,35 In 2006, 70% of new AIDS cases among men were attributed to heterosexual transmission. Among women, over 97% of cases were attributed to heterosexual transmission and tended to occur in young ages.1,34,35

Sentinel surveillance among MSM in 2000–02 made evident prevalences of 18–20% in the capital city, Bogota.36 Among pregnant women, from a low of 0.06% in 1991, rates increased to 0.4% in 1999 and 0.6% in 2003.37 Among FSW, prevalences were around 0.7–0.8% in Bogota.37

An assessment of the drug scene of Bogotá found youth recently engaged in the habit of injecting cocaine and heroin. Most were polydrug users and reported low injection frequencies, with low seroprevalences for both HIV and HCV (<2%), however, high frequencies of syringe sharing and unprotected sex may favour HIV spread.38

Ecuador

An estimated 23 000 people were living with HIV in 2005 in Ecuador, with a population of 13 228 000, giving a prevalence of 0.3% among adults.1 Of newly reported cases in 2004–05, 77% were among males, of which less than one-third reported sex with other men, suggesting that homo/bisexual transmission has been underreported.8

Different studies made evident high prevalences of HIV among MSM (14–17% in the capital city, Quito, and 23–28% in Guayaquil),1,39 but low prevalences (1.7%) among FSW and pregnant women (0.4–0.6%).39

An adult HIV prevalence of 0.7% is estimated in Venezuela, with a total population of 26 749 000.1,47 Between 1983 and 2002, Venezuela reported 20 825 AIDS cases to PAHO, but underreporting seems probable.47 The epidemic is concentrated on MSM, and transmission between males seems to account for 65% of total HIV infections, with increasing proportions of young men aged 15–25 becoming infected,48 while 28% of all adult cases occur in women.1,48 Data are sparse, since the country lacks an established surveillance system.

Since the early 1980s, people living with HIV/AIDS (PLWHA) in the region have been struggling for care within public health systems, effective coverage by insurance companies, protection against labour-rights violations and discriminatory practices. A good part of the efforts of community groups has been to provide help due to the lack of support from the state.

The initiatives that emerged in the 1990s opposed not only stigma and discrimination, but also the inequalities that were reinforced by the pandemic, particularly in regards to access to treatment. Since 1996, with the launching of HAART, the north–south divide became more visible, as access to new medications was hampered by their high costs.(72) The 1990s were marked by the World Bank’s controversial position that developing countries should focus on preventative initiatives rather than treatment.(73)

Brazil was the first middle-income country worldwide to reject this prescription with the full implementation of a national HIV/AIDS strategy for prevention as well as treatment. Since 1996, Brazil has guaranteed universal access at no cost at the point of delivery to ARV. Adherence to ARV treatment, which was thought to be problematic, not only within the country but also among international agencies, was found to be comparable with adherence observed in the US and Europe in a countrywide study from 2003 (75% of the patients were taking more than 95% of the prescribed pills).(74) Unfortunately, one-third of drug-naıve patients have been initiating the treatment at an advanced stage of the disease.(75)

In recent years, the question of the right of access to AIDS medications has been focused on patents, the role of international pharmaceutical companies (IFC) and the associated costs of ARV.(76,77) Brazil’s resilience against pressures from IFC, combined with other regional developments, such as the creation of the Horizontal Group of Technical Cooperation on HIV/AIDS, fostered universal access to prevention and treatment as now promoted by international agencies.(78)

The establishment of the Global Fund to Fight AIDS, TB and Malaria, in 2001, the Declaration of Commitment signed by 189 countries at the United Nations General Assembly Special Session on HIV/AIDS (UNGASS), also in 2001 and the ‘3 by 5’ Initiative (i.e. the WHO initiative to provide ARV to 3 million people in developing countries by 2005) put the synergy between prevention and treatment as a centrepiece in the implementation of national responses to the epidemic.(78) Also, lessons from delivering ARV in resource-limited settings fostered treatment roll out (79,80).

Brazil has one of the largest populations of individuals (200 000) receiving ARV, free of charge, worldwide and it is trying to reduce the costs of ARV, including the issuing of a compulsory license in 2007.(82)

Latin America shares with other regions some of the gaps and challenges that remain to be overcome such as the disadvantages that afflict women in regard to access to information, their ability to negotiate safer sex and gender-based violence.1,63

79 Attawell K, Mundy J. Provision of antiretroviral therapy in resource-limited settings: a review of experience up to August 2003. Available at: http://www.who.int/3by5/ publications/documents/en/ARTpaper_DFID_WHO.pdf (Accessed April 25, 2008).

80 Farmer P. Pathologies of Power: Health, Human Rights and the New War on the Poor. Berkeley, Los Angeles and London: University of California Press, 2003.